PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 657 
ROSTRICELLULA sp. 2 
Plate 131, D, figures 28-32 
Shell small, length and width about equal; apical angle about 95°. Greatest 
width anterior to the middle. Costae numbering 5 on the fold, 4 in the sulcus, 
and 7 or 8 on the flanks. 
Pedicle valve slightly less deep than the brachial valve and with a moderately 
convex lateral profile. Anterior profile broadly and gently convex. Sulcus origi- 
nating 5 mm. anterior to the beak ; umbo gently rounded; sulcus shallow, occupy- 
ing about half the width. Tongue long and narrow. Flanks narrow and steeply 
descending to the margins. 
Brachial valve with lateral profile like that of the pedicle valve; anterior pro- 
file moderately strongly convex; umbonal region moderately swollen; fold low 
and rounded, not elevated strongly at the anterior. Flanks rounded and with 
precipitous sides. 
Measurements in mm.—117235, length 8.1, brachial length 7.4, width 8.3, 
thickness 5.7. 
Figured specimen.—117235. 
Horizon and locality—Upper Wardell formation in Virginia: At Mannville 
School, Clinchport (T.V.A. 188-NW) Quadrangle. 
Same (?) horizon in Tennessee: On Little Mulberry Creek on the road up 
Sycamore Valley, Back Valley (T.V.A. 161-SE) Quadrangle. 
ROSTRICELLULA sp. 3 
Plate 139, E, figure 54 
A figure of this specimen is introduced to show the character of the micro- 
ornamentation common to many species of Rostricellula. This consists of fine, 
wavy, concentric fila. These are irregular and often somewhat discontinuous. 
They are also variable in the degree to which they approach fine lamellae and 
are often longer in the swales between the costae than on the sides and are fre- 
quently worn off the crests of the costae. In places where variable in length 
these fila or minute lamellae give the impression that the surface is granulose. 
Figured specimen.—117237. 
Horizon and locality—Lower Prosser formation in Minnesota: In the road 
cut 1.2 miles east of U. S. Highway 52 on the south edge of Cannon Falls, 
Goodhue County. 
Family LEPIDOCYCLIDAE Cooper, new family 
Rhynchonellacea with concave deltidial plates (?) in the pedicle valve and a 
cardinal process in the brachial valve. 
Genus LEPIDOCYCLUS Wang, 1949 
Lepidocyclus Wane, Geol. Soc. Amer. Mem. 42, p. 12, 1949. 
